Furnace



J HARRINGTON.

FURNACE.

APPLICATION FILED DEC. 10, 1915.

Patented Jan. 3, 19229 2 SHEETS-SHEET I.

J. HARRINGTON.

FURNACE.

APPLICATION FILED DEC. 10. 1915.

Patented Jan. 3, 1922.,

SHEET 2 2 SHEETS n W W 1 a M M ww- A UNHTED stares stance.

JOSEPH-1 EHARRINGTON, OF CHICAGO, ILLINQIS. K

3 T all whom it may concern citizen of the United States, and resident county of Cook, and State ofeQxtend rearwardlyfrom the foot of the fuel Be it known that I, Josnrrr HARRINGTON, a

Chicago, Illinois, have invented certain new and useful Improvements in Furnaces, of which the following is a specification,-and which are illustrated in the accompanying drawings,-

forming a part thereof. 7

The invention relates to furnaces and more particularly to the provision of mechanical means for feeding the fuel and accomplishing its travel through the Zone of combustion, and for discharging the ash into a suitable receiver. The invention is more especially applicable to furnaces in which the rate of the combustion of the fuel is comparatively slow, as in house heating steam boiler plants..

The object of the invention is to provide a furnace with mechanical stoking means which shall be eflicient in operation and which may be constructed to require substantially no attendance for long periods and then only for the purpose of replenishing the fuel-supply and emptying the ash receiver.

In the accompanying drawings,

Fig. 1 is a central longitudinal sectional view showing details of a furnace equipped with apparatus provided by the invention, the motor for operating the stoking means being shown in elevation.

Fig. 2 is a central sectional view of the motor, some of the parts being shown in elevation, i

Fig. 3 is a plansectional view'of the furnace, some of the partsbeing broken away,

Fig. 4 is a sectional view taken on' the line 4-4 of Fig. 2,-

' Fig. 5 is a perspective view showing a de-' tail of the motor, and

Fig. 6 is a detail sectional view taken on the line 66 of Fig. 1.

The drawings show the apparatus applied to a sectional steam boiler 10 of a general form commonly employed for house heating service. The steam boiler 10 may comprise a plurality of cast iron sections 11 and 12, some of the sections, as 11, being formed with water spaces 13 which arch over a fire box with intervening flue spaces 15, and one of the sections, as 12., being formed to provide a water space 16, which constitutes the back wall of the fire box chamber. In carrying out the invention, a fuel hop- Specifieation of Letters Patent.

FURNACE.

per 17 is provided at the front of the fire box 14 and a set of alternating movable and stationary transverse grates, as 18, 19, 20 and 21,

hopper to form a series of descending flights or steps for supporting the fuel bed. An imperforate horizontal partition or wall 22 serves for dividing the space below the grates into an air supply chamber 23 and an ash pit 24, the air supply chamber 23 being directly Patented Jan 3, 11922.

Application filed December 10, 1915. Serial No. 66,087,

below the grates. Preferably the partition 22 extends from the front end of the furnace to atransverse water beam 25 adjacent its rear end, the two ends of the water beam 25 being preferably connected with the water spaces '13 of the boiler sections 11 in any convenient manner, (not shown).-

Cast iron side walls 26, 27, and a floor plate 7 28 serve for enclosing the air supply chamber 23 and ash pit 24 -at the sides and bottom. These chambers are preferably also closed at the front,'as by doors 29 and 30, the door29 being provided with a movable damper 31 for controlling the admission of air to the fuel.

The grate 18'may extend from side to side of the furnace in one piece, in which case its fuel hopper 17. As shown, this grate is slidingly supported for horizontal reciprocating movement as by resting at its opposite ends upon brackets, 32, one of which is formed uponeach of the side walls 26 and 27. upon the inside. Preferably only the inner edge forward portion constitutes the bottom of the portion, as 33, of the grate 18 is made foraminous,- the openings through all of the grates being shaped in accordance with the character of the fuel to provide for the passage of a Y suitable amount of air while substantially "preventing the sifting of fuel'into the air supply chamber 23. v

The grates 19 and--21 are stationary and each of, these grates is formed in one piece. The grate 19 issup'po'rtedby having its opposite ends rest upon bracket lugs, as 34,

formed upon the corresponding side walls 26 and 27 Other bracket lugs, as 35,- formed upon the side walls 26 and 27 serve for supporting the grate21 at its front edge and the rear edge of this. grate extends over and is supported by the water beam 25. In the arrangement shown, the openings, as 36 and 37 through the grates take the form of narrow slits, theopenings 37 being'confined to the forward portionof the grate 21. The grate 20 is reciprocable and is of-such width as to extend below the rear edge of the grate 19 and over the forward edge of the grate 21 in ers, the grate 20 is preferably composed of,

a seriesof independent grate bars or sections 38, having relative movement. When constructed in this way a transverse beam 39 preferably-extends from side to side of the furnace between the side walls 26 and 27, for slidingly supporting the forward ends of the grate bars or sections 38. in any case the reciprocation of the grate 18 serves to withdraw a layer of fuel from the hopper 17 and move it progressively within the fur nace until it is deposited over the rear edge of the grate 19 on to the grate 20. Similarly the reciprocation of the grate 20 serves to continue the reward movement of the fuel, the rate of reciprocation of the grates 18 and 20 being preferably so regulated with reference to the amount of air supplied for combustion that only the ash is delivered over therear edge of the grate 21.

Preferably the ash pit 24 is provided with a contracted throat 40 and this throat is to be substantially filled with the ash to serve as a seal to prevent the passage of air from the ash pit into the fire box. As shown, the section 12 of the boiler 10 is constructed with a forwardly projecting inclined portion 41. When constructed in this way the contracted throat 40 of the ash pit chamber extends from side to side of the furnace between the part 41 and the water beam 25.

A gradual withdrawal ofaccumulations of the ash from within the throat 40 and the deposit of the same into the main chamber of the ash pit 24 may be accomplished by the use of a reciprocating floor plate and pusher generally designated 42. This member preferably extends between the side walls 26, 27, and comprises an inclinedportion 43 which constitutes the floor of the throat 40, and a forwardly facing upright portion 44 which constitutes a pusher for advancing the ash within the main chamber of the ash pit 24. The member 42 is slidingly supported, as by the engagement of the lower edge of its upright portion 44 with an inclined portion 45 of the floor plate 28, and by providing, a shelf 46, which extends between the side walls 26, 27, below the rear edge of the inclined portion 13.

Rock shafts 47 and 48 are conveniently employed for accomplishing the reciprocation of the movable grates, as 18 and 20, and for actuating the member 42, respectively. These shafts preferably extend transversely through the furnace chamber below the parts which are to be reciprocated thereby. When so arranged each shaft is journaled in the side walls 26 and 27, and has one end projecting beyond the corresponding side actuating element. As showp, a crank arm 49 is directly applied to the projecting end of the rock shaft 47. Preferablya part of this crank arm, as 50, extends below the rock shaft 47 and servesfor actuating the rock shaft 48. To this end a crank arm 51 is applied to the projecting end of the rock shaft 48, and a link 52 extends between this crank arm and the part 50 of the crank arm 49.

As the variation in the amount of ash con tained in different fuels will make it desirable to regulate the rate of reciprocation of the member 42 with reference to the rate of reciprocation of the movable grates, as 18 and 20, provision is preferably made for adjustably connecting the link52 with the art 50 of the crank arm 49. As shown, the part 50 is provided with a plurality of holes 53, which are located at difierent distances from the axis of oscillation of the crank arm 49, and a pin 54, which serves for connecting the link 52 with the part 50, may be inserted in any one of these holes. Operative connection between the rock shaft 47 and the grate 18 is accomplished through the use of a pair of crank arms 84,

one mounted on the rock shaft just within each of the side plates 26. and 27. A link 55 connects each of these crank arms with a lug 56 which depends from the corresponding end of the grate 18. In order that the travel of the'grate 18 may be adjusted, the crank arms 84 are each provided with a series of holes 57 into any one of which the overturned end of the corresponding link.

55 may be inserted.

Qperative connection between the rock shaft 47 and the grate 20 is obtained'by providing the rock shaft 47 with a plurality of crank arms 58. When the grate 20 is composed of a series of independent grate bars 38, as shown, one crank arm 58 may be provided for each grate bar 38, and these crank arms are arranged along the rock shaft 47 in alinement with the several grate bars 38. In this event a lug 59 projects from therear end of each grate bar 38, and overhangs the transverse supporting bar 39. Each crank arm 58 isprovided with a series of holes 60, and a link 61 is connected at one end with the lug 59 of each grate bar 38,-- the opposite end of each link being adapted for insertion into one of the holes 60 of the corresponding crank arm 58. Relative movement between the adjacent grate bars 38, while still providing for a substantially uniform reciprocation of the entire number of grate bars, is obtained by inserting the forward ends of adjacent links 61 into holes 60 of the corresponding crank arms 58 which are located at different radial distances from the axis of the rock shaft 47. The rock to" reciprocate the member 42 by engaging lugs 63 which are formed upon the under side of the inclined portion 43. Any convenient means may be employed for swinging the crank arm 49 to actuate the rock shafts 47 and 48. When the furnace is to be employed for house heating, the arrangement may be such as to use the domestic water supply as. the source of power :with provision for permitting the crank arm 49 to be swung by hand when occasion requires, as in starting the fire. The drawings illustrate the use of a water motor comprising a cylinder 65, a reciproeating piston 66, and a piston rod 67. The cylinder 65 is pivotally secured to a fixed support at one end, as at 68. The outer end of the piston rod 67 may be provided with a notch 69 for engagement with a pin 7.0 on the crank arm 49, and with a handle 71 to be used in lifting the piston rod out of engagement with the pin 69, when the crank arm 49 is to be actuated by hand. The pivotal mounting of the cylinder 65, as at 68, serves both to permit the oscillation of the piston arising from its connection with a swinging crank arm, as 49, and also to permit the lifting of the piston for disengaging the notch 69 from the pin 70.

The cylinder 65 is provided with a port, as 72 and 73, adjacent each end and studs, as 74, 75, project from the two sides of the piston 66 for engaging the end walls of the cylinder to lprevent the piston overrunning the ports. pipe 76 connects each port 72, 73, with a valve casing 77. Water supply and exhaust ipes 7 8, 79, also connect with ca'sing 77, an an oscillating valve 80, within the casing, serves for establishing com: munication between the water supply and exhaust pipes 78, 79, and the two ports 72, 73, of the cylinder 65, in alternation.

The movements of the valve 80, are conveniently accomplished by gravity, as by the engagement of a weighted arm 81 with a pair of crank arms 82 and 83. As shown, the crank arms 82 and 83 are fixed upon the spindle 84 of the valveand the weighted arm 81 swings upon the said spindle, as a pivot. A lug 85 of the crank arms 82, 83 extendinto the path of the arm 81.

In order that the position of the valve 80 may be changed abruptly at the end of each stroke of the piston 66, pI'oyision is made for raising the arm 81 during the movement of the piston in each direction. As shown, an upstandin-g'arm 86 is rigidly connected with the outer end of the piston rod 67 and a slotted pitman 87 is pivotally connected with the higher end of this arm. The slotted portion of the pitman 87 is bifurcated and each of its two parts, 88, 89 (Fig. 4), is guidedly supported in horizontal position having sliding engagement with one of a pair of bracket arms 90-which are carried by the wall of the cylinder 65. The arm 81 is also slotted and swings between the two parts 88, 89, of the pitman 87. A gib 91 (Fig. 5) serves for operatively connecting the arm 81 with the pitman 87 This gib has flattened end portions 92, 93, which run in the slots of the parts 88 and 89, respectively, of the pitman 87 and a round intermediate portion 94 which runsin the slot of the arm 81. If the parts he so proportioned that the arm 81 is brought to an upright position just before the piston 66 reaches the end of its stroke in each direction, the remainder of the movement of the piston will carry the arm to an inclined position from which it will fall by gravity for changing the position of the valve 80.

The rate of reciprocation of the piston 66 may be controlled by varying the quantity ofwater supplied through the pipe 78, as b the use of a needle valve 95. If desire provision may be made for automatically adjusting the needle valve 95, in accordance with variations in the temperature of the rooms which are to be heated, as by the boiler 10. As changes in the .rate of reciprocation of the grates 18, and 20, is preferably accompanied by changes in the amount of air supplied for combustion, the automatic means provided for adjusting the needle valve 95 should also serve for adjusting the furnace damper, as 31. For simplicity of illustration, a pair of sole.- noids 96 and 97 are provided and the supply of electric current to both of the solenoids is conventionally represented as being controlled by a thermostat 98 which may be located in the room to be heated. Changes in the position of the core, as 99, of the solenoid 96 may serve for adjusting the needle valve 95, as by connecting said core with a rack 100, and which is operatively connected'with'a gear 101 mounted on the stem of the needle valve. Similarly, changes in the position of the core, as 102, of the solenoid 97 may serve for adjusting the damper 31, as by connecting the damper to said solenoid core with a chain 103. The quantity of fuel withdrawn from the'hopper 17 at each stroke of the grate 18 may be regulated by the use of a vertically movable fuel gate 104 (Fig. 1). As shown this fuel gate is adjustably secured against the adjacent section 13, of the boiler 10, as by screw bolts 105 which pass through slots, as 106, in the gate.

The feature of automatically regulating both the speed of the stoker and the draft controlling device in accordance with the temperature attained at the place to be heated is reserved for the reason that claims to this feature have been presented in my co-pending application for patent on heatvember 9, 1916.

I claim as my invention,-

1. The combination with a fire box having a rear wall, of a descending foraminous grate extending rearwardly from the front end of the fire box, the lower edge of the grate being spaced apart from the said rear wall of the fire box to provide a contracted throat for receiving ash delivered at the said lower edge of the grate, an imperforate partition extending forwardly from the said lower edge of the grate and dividing the space below the grate into an air supply chamber to which the underside of the grate is directly exposed and an ash pit chamber which extends under the said air supply chamber from the lower end of the said throat to the front end of the furnace, and a forwardly operating ash conveyor mounted in the bottom of the said ash pit chamber, the location of the said conveyor being such that the angle between the forward edge of the lower end of the said throat and the rearward limit of the zone of operation of the conveyor is less than the angle of repose of a heap of ashes delivered to the said ash pit chamber through the throat.

2. The combination with a furnace having a fire box, of a pair of horizontally disposed longitudinally separated transverse grates located at different levels, and a transverse series of horizontal grate bars located between the two first mentioned grates, each of the said grate bars extending under the adjacent edge of the higher grate at one end and over the adjacent edge of the lower grate at the other end and all of the bars in the series having longitudinal reciproeating, movement and the movements of the adjacent bars in the series being different in amount.

3. The combination with a furnace having a fire box, of a pair of horizontally disposed longitudinally separated transverse grates located at different levels, and a transverse series of longitudinally reciprocable horizontal grate bars located between the two first mentioned grates, each of the said grate bars extending under the adjacent edge of the higher grate at one end and over the adjacent edge of the lower grate at the other end and the reciprocating movements' of adjacent grate bars in the said series being different.

4. The combination with a furnace having a fire box, of a pair of horizontally disposed longitudinally separated transverse grates located at different levels, a transverse series of longitudinally movable horizontal grate bars located between the two first mentioned grates, each of the said grate bars extending under the adjacent edge of the higher grate at one end and over the adjacent edge of the lower grate at the other end, a transverse rock shaft, and a link connecting each grate bar of the said series with the rock shaft, the points of attachment of the links associated with adjacent grate bars to the rock shaft being located at different distances from the axis of oscillation of the rock shaft.

5. The combination with a furnace having a fire box which is closed at its rear end, of a foraminous grate having its rear end spaced apart from the rear end of the fire box, means for moving fuel progres- 7 sively over the grate from front to rear, an imperforate partition connecting with the rear end of the grate and extending forwardly therefrom below the grate to provide an air supply chamber to which the under side of the grate is directly exposed and an ash pit which extends under the said air supply chamber to the front of the furnace, the

vsaid closed end of the fire box and the said partition being so formed as to constitute a contracted throat for the accumulation of ash to seal the opening between the ash pit and the fire box beyond the rear end of the grate a horizontally movable reciproeating plate mounted in the ash pit below the said throat and a pusher connected with the forward edge of the plate, the angle between the said forward edge of the plate and the adjacent margin of the lower end 0f the throat being at all times less than the angle of repose of a heap of ashes resting on the plate.

6. A combination with a furnace havinga fire box, of a plurality of sets of grate bars in stepped relation, and means for moving all of the indivudal bars of one set relatively to each other and to the bars of the 7 adjacent sets.

7 In a furnace, in combination, a plurality of grate bars arranged in stepped relation,

one bar comprising a plurality of independently movable juxtaposed sections, and means acting on the several sections of the last mentioned grate bar for reciprocating said grate bar and imparting relative movement to adjacent sections thereof.

8. In a furnace, in combination, a fire box, an ash pit, a grate constructed to provide an ash receiving throat extending to the ash pit, a horizontally movable recipro- =cating plate mounted in the ash pit below the throat and a pusher at one edge of the plate and movable therewith, the angle between that edge of the plate at which the pusher is located and the adjacent end of 12' the throat being at all times less than the angle of repose of a heap of ashes resting on the plate.

9. A furnace comprising a rear wall having its lower portion downwardly and forwardly inclined, a grate having its rear margin spaced from said inclined wall portion forming a contracted ash throat, an ash chamber underlying said grate, and having an imperforate upper wall spaced from said grate, a continuously acting ash conveyor comprising an inclined plate and a pusher face at the'bottom of said ash throat and forming an extension of said inclined wall portion whereby an accumulation of ashes shall-be maintained in said throat to prevent passage of air and at the same time ashes in excess of the amount required to prevent passage of air shall be continuously removed.

10. The combination with a furnace grater constructed for the discharge of ashes over the rear end of the same, of a movable ash receiving table located under the rear end of the grate and'means for reciprocating the said table in a plane substantially parallel With the under side of the grate but maintaining the forward edge of the table at all times at such a distance in front of the rear end of the grate that theangle between the forward edge of the table and the rear "end of the grate is less than the angle of repose of a heap of ashes resting on the table.

JOSEPH HARRINGTON. 

